Common Milkweed, asclepias syriaca, seeds!
Create a Monarch butterfly way station!
If you’ve never grown anything from seed, growing milkweed is a great way to start. You will develop skills applicable to starting other types of plants, and you could become part of a cross-continental chain of waystations dedicated to sustaining the entire lifecycle of monarch butterflies. Your garden could be a butterfly waystation!
Germination: Milkweed requires a cold, moist stratification period. This means that the seed after being harvested, dried and cleaned needs to have a “chilling” period. Nature’s method is done through the winter weather. To obtain similar results the seed should be mixed with moist sand, sealed in an airtight container, and placed in storage 33-38 degrees Fahrenheit. (A refrigerator works best). The period of chilling varies with the species. A. syriaca requires 30 days of cold stratification. A. incarnata requires 30-90 days of cold stratification. Some growers opt to soak the A.incarnata seed in hot water (190 degree F.) for 12 hours. www.usda.gov suggests this process be repeated for a total of 3 times before sowing the seed. 2. The seed can be sown in open trays using a commercial seed starter mix. It is usually better to sow seeds 2-3 per cell in a deep flat (cell counts vary). Cover very lightly with soil. I have found a 38 ct. 4 inch deep tray to work well allowing room for root growth and the least amount of disturbance when transplanting. However, commercial seeding trays can work if that is what is available. If the trays are to remain inside, the air temperature should be maintained between 65-75 degrees F. A heating pad can be used underneath to help with germination. Keep the soil moist by misting or spraying. Do not overwater! A plastic cover can be placed over the tray until germination. Light is very important for continued growth and can be obtained by using a fluorescent overhead fixture. A timer placed on the light source will assure 14-16 hours of needed light. Plants usually take 4-8 weeks to reach a stage where they can be moved to a cold frame to harden off. 3. If you would like to sow in trays outside, you can follow the same instructions above, eliminating the need for the cold stratification as the outside temps will take care of it. Just keep in a protected area and check occasionally, especially as the weather warms. They will need watering after the last frost. Also, rodents can be a problem. A wire mesh covering can help. Again, a simple cold frame can speed the germination and growing time, but requires more diligence.